The Histology/Neuropathology Core of the program project is located at the Bedford Veterans Affairs Medical Center. The specific aims of the core are: 1) to fully characterize the anatomical pathology of animal lesions produced in projects 1 and 3 by defining the spatial distribution of lesions and the extent of oxidative injury affecting histochemically defined neuronal subsets;. 2) to determine the light and ultrastructural changes produced by manipulation of superoxide dismutase (SOD) expression in cell culture systems (project 2), 3) to perform detailed postmortem analysis on human brains studied in the center for the conformation of diagnosis, the detection of specific patterns of oxidative injury in affected neuronal classes and the detection of clinical variants associated with specific genetic abnormalities. Postmortem specimens will be studied with the same methods used in experimental animals to determine the validity of SOD manipulation as animal models for neurodegenerative diseases and aging. Specific methods include three dimensional serial reconstruction of lesions and quantitation with computerized image analysis, definition of localized tissue injury with glial fibrillary acidic protein staining, detection of DNA oxidation in situ with the terminal transferase method and specific antibodies to 8-OH deoxyguanosine; detection of protein oxidation using thiocarbohydrazide binding assay and specific antibodies to nitrotyrosine; detection of lipid peroxidation with the thiobarbituric acid method in animals and the hydroxynaphthoic acid hydrazide/Fast Blue B method in postmortem tissue; SOD immunocytochemistry and enzyme histochemistry; and detection of thiol specific antioxidant protein. These determinations will permit us to accurately define lesions, the extent and nature of oxidative injury and the effects of experimental therapies such as those proposed in project 3 (tetanus-SOD fusion protein). Postmortem human tissue will be obtained from the Bedford VA, Massachusetts General Hospital (MGH) and Johns Hopkins University. In the past year, 56 autopsies, including 20 Alzheimer's disease (AD), 9 Pick's disease, 5 Lewy body disease, 1 amyotrophic lateral sclerosis (ALS) and 9 controls have been performed at Bedford - an autopsy rate of over 80%. Additional ALS specimens will be obtained from affiliated clinics at MGH and Hopkins. A range of both fixed and deep-frozen tissue samples are acquired and stored using uniform acquisition procedures to ensure accuracy and reproducibility and fulfill the specific requirements of affiliated investigators. A comprehensive database is maintained that includes quantitative morphometric, histochemical, and biochemical analyses to facilitate clinical-pathological correlative studies of neurochemical, histological, and neuropsychiatric aspects of neurodegenerative diseases including AD, Parkinson's disease, Huntington's disease, and ALS. The comprehensive facilities available to perform detailed quantitative histology and anatomically define injury in a consistent manner will provide a unique resource.